Featured Element:
Bismuth

Bismuth is a brittle crystalline which is slightly pinkish in its elemental form. It is a post-transition metal, which chemically resembles Arsenic and Antimony. Of all the metals it has the greatest electric resistance, and the second lowest thermal conductivity (only beaten by Mercury). Bismuth has an unusual property that it expands when it freezes (much like water turning into ice). Bismuth is found in 9 parts per billion in the earth’s crust. Unlike other heavy metals, such as Lead, Antimony, or Mercury, Bismuth is not particularly toxic. It has many isotopes whose atomic mass ranges from 185 to 217, but only 209Bi is considered stable. In particular, Bismuth-213 was tested in cancer treatment as part of the Target Alpha Therapy (TAT) program.

Interesting Facts:

Discovered in 1753 by Claude Geoffroy the younger. The word Bismuth comes from the German “weise masse” which translates to white mass.

Bismuth 209 was thought to be stable, but in 2003 it was discovered to have an extremely slow rate of decay. Its half-life is 1.9 * 1019 years – more than 1 billion times the current age of the universe.

Bismuth has a low melting point for a metal and its liquid form is denser than its solid form.

Solid bismuth tends to form a unique crystalline structure with a prismatic surface. This causes unique coloration due to the different oxidation states of bismuth that form thin oxide layers on the surface. The crystalline structure can also be manipulated into rhombohedral, monoclinic, tetragonal, and cubic shapes by varying the pressure of formation.

Bismuth has uniquely low toxicity for a heavy metal, so it has gained popularity as a replacement for Lead.

Sources:

Bismuth is found in the minerals Bismuthinite and Bismite, or as a by-product in the refinement of Gold, Silver, Lead, Tin, Zinc, and Copper. China, Peru, and Mexico are the three largest producers of Bismuth, with China producing nearly 75% of the Bismuth found in these three countries.

Industrial Uses:

Bismuth subsalicylate is the chemical name of Pepto-Bismol, a well-known medicine for stopping indigestion and diarrhea. Bismuth is also used in cosmetics, paint, and medicines. Alloys of bismuth are used as low-melting safety devices for fire detection and extinguishing. They are also used in the making of sharp castings of objects that are sensitive to extreme heat because it expands 3.32 percent upon freezing. Bismuth is sometimes used in alloys of other metals to help compensate for contraction. Bismuth is also sometimes used to replace Lead in bullets. The U.S. Naval Weapons Center uses Bismanol, a high coercive force magnet.